Gas combustion turbines are used for a variety of applications such as driving an electric generator in a power generating plant or propelling a ship or an aircraft. Firing temperatures in modern gas turbine engines continue to increase in response to the demand for higher efficiency engines. Superalloy materials have been developed to withstand the corrosive high temperature environment that exists within a gas turbine engine. However, even superalloy materials are not able to withstand extended exposure to the hot combustion gas of a current generation gas turbine engine without some form of cooling and/or thermal insulation.
The instrumentation of a component such as a blade or vane within a gas turbine typically includes placing wire leads on the balance wheel, which continue on to the blade airfoil. The wire leads are typically held together by an epoxy. These wires are routed from within the component to the turbine casing. The pressure boundary of a component may be breached to introduce a sensor such as a thermocouple and a braze is back filled to hold the thermocouple in place. Each thermocouple sensor has wire leads coming out of the component that are connected back to a diagnostic unit. Instrumenting a plurality of components in this manner results in an extensive network of wires just for monitoring the single operating condition of temperature.